Method of securing caps to projectiles.



No. 65!,969. Patented lune l9, I900. 0. HARTMANN. METHOD OF SECURING GAPS T0 PROJEGTILES.

(Application filed Nov. 17, 1899.) (No Model.)

Unrrnn grates Parent @rrrcn.

os'can HARTMANN, or ESSEN, GERMANY, ASSIGNOR T0 ,rnmn. KRUPP,

or SAME PLACE.

METHOD OF SEGURiNG CAPS T0 PROJECTILES.

SPECIFICATION forming part of Letters Patent No. 651,969, dated June 19, 1900. Appliustionfiled November 17, 1899. Serial'No- 737,371. (No model.)

To all whom it may concern..-

Be it known that], OSCAR HARTMANN, engineer, a citizen of the German Empire, residing at Essen, Germany, have invented certain new and useful Improvements in Methods of Securing Oaps to Armor-Piercin g Projectiles, of which the following is a specification.

My invention has reference to armor-piercing projectiles which usually have their points covered by caps of a soft tough material; and it consists in an improved method of securing the cap to the projectile.

The caps were heretofore secured to the projectiles by means of hard solder, which method, however, has been abandoned, because the degree of heat to which the point of the projectile had necessarily to be raised seriously afiected the hardness of the same. Lately the practice has been to secure the cap by foreing'the material of the same into an annular groove in the projectile. The objection to this last method of securing theeap is thatowing to the groove turned into the point the latter is apt to break-on striking the armor-plate. My improved method neither requires heating of the point to a de-' gree capableof reducing the hardness of the point nor is it necessary to turn the grooves into the projectiles, while, as demonstrated by experiments, it efiects a perfect union of the cap and projectile. My method consists in turning the inner end of the cap to the shape of the point of the projectile and grinding it upon the point and then uniting the two parts by soft solder.

My invention will be best understood by reference'to the annexed drawings, in which- Figure 1 shows the projectile in elevation and the cap in vertical section a short distance above the point. Fig. 2 shows the projectile and cap in their relative positions when soldering.

cap.

The cap Z), Fig. 1, which is bored out to the cup-shaped form 1), corresponding to the form of the point a of the projectile, is ground on Fig. 3 is an elevation'of the this point a to 'a perfect'fit, so that the sub sequent soldering should, as far as possible, extend over the whole of the contact-surfaces of the. two parts.

Forsoldering I use, by preference, a solder having a comparatively-low meltingpoint, less than 200 eentigrade. The cap b and the point a of the projectile are immersed into the molteusolder until both parts are heated to its temparatu re and are coated with solder. Finally the point a of the projectile, turned downward, as in Fig. 2, is pressed into the cup b of the cap I), which is filled with molten solder, forcing the surplus solder out.

What I claim is 1. The herein-described method of securiug the caps to armor-piercing projectiles, which consists in turning the interior of the cap to the shape of the point of the projectile, grinding the cap upon the point and then uniting the two parts by soft solder.

2. The herein-described method of securing caps to armor-piercing projectiles, which consists in first turning the inner end of the cap to the shape of the point of the projectile, then grinding the two parts together, then immersing the cap and the point of the projectile into molten soft solder until heated to the temperature of the solder and finally pressing them together after the interposition of soft solder. 1

3. The-herein-described method of secur ing caps to armor-piercing projectiles which consists in turning the point of the cap to the shape of the projectile, grinding the two parts together, heating the point and the cap approximately to the melting-point of the solder, covering the contact-surfaces with molten solder, and pressing them together.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses. j

I OSCAR IIARTMANN. Witnesses:

WILLIAM Essnnwnm, GEO. P. PET'II'I. 

